Sedimentation apparatus



March 25, 1941., 1 H, KNQWLES Y 2,236,434

4 SEDIMENTATION APPARATUS Filed Jan. '7, 1959 3 Sheets-Sheet 1 Flew.'

I6 15 T4' i ATroRNEY.

March 25,Y 1941. J. H. KNowLEs SEDIMENTATION APPARATUS -Fled Jan. 'A7,1959 3 Sheets-Sheet 2 BV. JOHN H.KNowLE5,

ATTORNEY.

March 25, 1941. J. H. KNowLEs SEDIHENTATlON APPARATUS Filed Jah.

7, '1939 3 Sheets-Sheet 5 1NVENTOR.

Gil

Patented Mar. 25., 1941 UNITED STATES .PATENT OFFICE K This inventionvrelates to sedimentation and similar types of apparatus and, morespecifically, to such as settlers, clariers, thickeners or decantingtanks as well 'asa sewage sludge digester units.' Such apparatuscommonly comprises a tank having a feed of incoming liquid and anoutflow means for ellluent frequen ly .providedby an overflow Weir oroutlet for clarified eill-uent. From theliquid usually held quiescentlyin the tank, suspended solids settle in the formv of sediment on thetank bottom. The sedimentI is impelled to a discharge section, usuallyto a depressed floor portion or sump, by means of travellingsubstantially radially extending arms that are equipped with rakingblades. Many such tanks or units 'have the liquid incoming thereto fedthrough a conduit arrangement 'that passes under the tank and terminatin a leg upstanding centrallyv of the tank. This seems to be `knowncurrently asa Siphon feed' although it is perhaps an inverted Siphon. l

'I'he up-leg orl flow delivery terminal of the siphon has been usuallyembodied in a hollow pier or column extending upwardly from the bottomof the settler tank. The pier or column has also been employed vforaording support for the sediment impelling rakearms and the means forrotating them. Such an assembly is shown in the Scott Patent Re. 20,072.I

The present invention has for its object the improving' or modifying ofthat arrangement, and

the invention hereof may be said to reside in making the boundary wallof the terminal of the incoming feed, rotatable and to carry with it therake arms, 'while having 4it movable around the upstandlng pier thatsupports the rotating members. The invention also involves :the conjointemployment of a stationary sealing member and a turnable sealing membercooperatively discouraging substantial leakage of incoming feed frombetween the xed and rotatingsections of the feed conduit.

For purposes of illustration,- I have chosen the best embodiment of theinvention now known to me.' but itis understood that I do not limitmyself to the details thereof other than as set forth in the appendedclaims, and even then, I reserve the right to equivalents thereof.

It is an object of the present invention to provide a sedimentationapparatus,- such as those hereinbefore mentioned having an improved ar-irangement for incoming feed liquid which is simple, highly eillcient inoperation and, at the same time, quite economical constructional-ly.

Another object is to -provide a feed arrangement' for l sedimentationdevices which will give in. creased volumetric flow over feedarrangements of the type previously mentioned with feed deliveryterminals of no greater size. and thus insure amore even delivery-and`distribution of the incoming liquidinto the body of the sedimentationdevice. v

A further object is to el ate costly concrete constructions hereinbeforenecessary while at .the

same time providing a feed arrangement of increased efficiency and ofmore economical design in and of itself.

With these and other objects in view, the invention consists in theconstruction and novel combination and arrangement of parts hereinaft/erfully described, illustrated in'theaccom- 'panying drawings, and setforth in the claims hereto appended, it being understood 'that variouschangesin the form, proportion and minor details of construction, withinthe scope of the v claims, may be resorted 'to without departing fromthe spirit of @the invention or sacrificing any of the advantagesthereof.

In the drawings- Fig. 1 is a top :plan view of a clarifier, preferablyof the Dorr type, having a feed arrangement for Aincoming liquidembodying features of the .present invention. v

Fig. 2 is a. vertical sectionalview substantially through a diameter of:the clarifier of Fig. 1, the feed arrangement being shown mostly inelevation. Fig. 3 is an enlarged vertical section'of the feed deliveryterminal embodying the features oi the invention.

, 3 Fig. 4 is an enlarged perspective view, with parts broken away, ofthe feed delivery terminal and some adjacent parts of 'the clarierbottom.

4In general, the invention is embodied in a sedimentation |tank having abottom and upstanding side wall, adapted to accommodate a body of liquidunder relatively. quiescent conditions and provided with a peripheraloverflow weir over which clarified supernatant liquor flows as eiliueni;into a launder tobe subsequently discharged. The bottom of the tank,preferably adjacent the central portion thereof may be provided with adeor sump for receiving sediment dethe bottom of the tank, otherwisepressed well poeited upon known' as sludge. Means are provided forimpelllng the settled sludge toward the central por'- tion of the tankbottom anddirectng it generally toward the sump from .which itmay bewithdrawn, continuously or intermittently through a suitable dischargeconduit. The sludge impelling means preferably will take the form ofradially extending arms provided with curved rake blades. which.incident to rotation ofthe arms, continuously impel sludge toward thecenter of the tank and eventually into the sump.

The novel features of the present invention reside in an improved andhighly emcient and economical arrangement for conducting and deliveringfeed liquid into the body of the tank. In the preferred form oi' theinvention there is provided below the bottom of the tank andconcentrically therewith a circular well constituting a liquid receivingsection for incoming liquid supplied thereto by a conduit extendingsubstantially horizontally underneath the tank bottom.

A stationary and substantially rigid column rises from the center of thewell thus providing an annular space between the column and the walls ofthe well which constitutes the said liquid receiving section. The columnextends upwardly and preferably terminates in a flared manner at a pointsomewhat above the normal liquid level.

in the tank as determined by the eilluent Weir. The dared top of thiscolumn supports, in rotatable manner, a depending tubular member whichextends downwardly substantially to the bottom of the tank and is oiapproximately the same internal diameter as that of the well orliquidreceiving section. The lower portion of the tubular member has-.a solidwall which dednes, with vthe central column, an annular space throughwhich incoming liquid flows upwardly from th'e yliquid receivingsection, while-the upper portion of the tubular member has walls whichare slitted, preferably vertically or otherwise arranged to permit theupowing liquid to flow or diffuse outwardly and substantlialyhorizontally. The rake arms previously mentioned are attached to andcarried by the tubular member at its lower solid portion and means,lsuch as struts or tie rods, may be provided for strengthening thestructure. The flared top of the column carries a motor which, through asuitable train of gearing, rotates the depending tubular member and therakes carried thereby at a relatively slow and constant speed forimpelllng settled sludge toward the discharge sump as previouslyindicated. A vertical cylindrical baille may surround the upper openportion of the tubular member for directing the ow of incoming liquiddownwardly and means may be provided adjacent the lower end of thetubular member for eil'ecting a seal between the same and the contentsofthe tank.

Referring particularly to the drawings, the reference numeral indicatesa sedimentation tank, here illustrated as a clarifier of the Dorr type,having a bottom I, sloping slightly toward the center, and an upstandingperipheral marginal wall 1. Incoming` feed liquid enters the tankcentrally thereof through a supply pipe 8, extending horizontally underthe tank bottom, clarifled eilluent passes over the. weir I into theperipheral launder Il and discharges through pipe Il, while sludgecollected in the sump .I 2 is withdrawn continuously or intermittentlythrough the sludge discharge pipe I3, all in'well-known manner. Y

In affording the features of the present invention there is providedeoncentrically of thetank, below the bottom thereof and.communicatingwith the interior thereof, a well Il, which is gen erally constructed of.concrete Aintegral with the bottom'wall of the tank. Extending upwardlyfor a short distance from the bottom of the well Il and centrallythereof is a base member II, also preferably of concrete, forming apedestal for the support of an upstanding stationary column as will bepresently described. 'I'he annular space deilnedby the pedestal I5 andthe side wall of the well Il provides a liquid receiving section I6 intowhich the influent conduit 8 discharges as clearly indicated.

I'he pedestal I5 supports in stationary and rigid manner an upstandingcolumn I1 which may have, at its lower end, an annular ange I8strengthened by ribs I8 so that the column may be rigidly andstationarily attached to the pedestal by bolts 28 embedded in thepedestal and passing through the flange I8. The column I1 preferablytakes the 'form of a metal tube. In centain instances it may, ifdesired, be filled with concrete or other strengthening substance, a1-though the column may be formed entirely of concrete or other substanceand be integral with the pedestal I5, although the structure illustratedis that preferred, being highly satisfactory in operation and possessingconsiderable economic advantage. 'Ihe column I1 is provided, at its top,withv an outwardly dared portion generally indicated at 2I eitherintegral therewith or rigidly 25 'attached thereto. 'I'he flared portionthus provides a platform 22 of enlarged are'a for the support ofcooperative elements presently .to be described. v

Fixedlyattached to the "tcp of the platform 22 by means of bolts 23 is aspider member formed of a base section 2l and spider arms 25 whichsupport at their outer extremities an annular bearing means preferablyin the form oi a ball ,race 28 containing the ball bearings 21. Theballs 21 support, in rotatable fashion, a rotatable annular member orturntable, taking the form of a bull ring 28 which is provided with gearteeth on its inner annulus. Also rigidly supported from Athe platform 22by means of a suitable beam or other type of support 28 is a relativelylarge platform 33 upon which is mounted a motor 3'I, preferably of thevertical shaft type, which actuates a pinion 32 in mesh with the gearteeth on the inner annulus of bull ring 28 so as to rotate the same uponthe ball bearings 21 at a desired speed. 'I'he platform 38 may alsosupport the innerend of a walkway or bridge 83, seen in Figs. l and 2.by means 'of which access may be had to the platform and its associatedmechanisms At suitable intervals about the periphery of the bull ring orturntable 28 are rigidly attached elbow members 34 which .carrydownwardly depending carrying members in .the form of angle Airons orT-shapes 35. The carrying members 35' are ilxedly attached adjacenttheir lower ends to a tubular member 38 which' extends downwardly andterminates a short` distance above the bottom of the tank. y In theembodiment shown the tubular member 38 is seen to have rigidly attachedthereto, at opposite diametrical points. the rake carrying arms 31 whichcarry the sedi,- ment raking blades 38. While the rakearms 3.1 are shownto be rigidly attached to the rotatable v ried by the tubular member inother desired manner, for instance, in the horizontally and verticallyswinging manner shown in the patent to Scott No. 2,122,383. In the caseof rigidly attached raking arms the structure may 4be strengthened andbraced by one or more tie rods or struts 38 extending through thetubular mem- I ber and rigidly attached to the inside wall of the sameat points wherethe rake arms are Joined to 65 .tubular member 33 theymay, ofcourse. be carthe tubular member. Thus the torque, incident todeposited sludge opposing the rotary move:l

ment of the raking arms, is transmitted directly through from one arm tothe other and thus acts lupon the tubular member 35 and its carryingmembers 35 to only avery limited extent. It is obvious that operation of'the motor 3l will .rotate the bull ring 28 throughcooperation of thepinion 32 and the ring gear .which will thus effect rotation of thecarrying members 35 and the tubular member 35 to actuate raking arms 31and cause the blades 38 to `impel sedimented material toward the centerof the tankand eventually into the sump I2.

n win be seen that the inoming liquid wm `enter the liquid receivingsection I5 from the supply pipe 8 and will then pass-upwardly oonnedwithin the tubular member 35 until it reaches the upper end of the samewhich may be at any desired elevation but is preferably below the normaloperating liquid level as dened by the overflow weir 9.A As the liquidleaves the upper end of the tubular member it will, of course,begin toow or diffuse outwardly and horizontally substantially las indicated bythe arrows in Fig. 3. `Instead of the angle irons 35 at relativelywidely spaced points for supporting the tubular member 35, the same maybe supported by another tubular member having elongated slits to permitthe liquid to pass outwardly,`

,or the tubular member 35 may extend upwardly preferred, however, sinceit offers a free-and .un-

and be joined to the elbows 34, with elongated slits being-provided inits upper portion to permit the liquid to ow outwardly and enter thebods1 of the tank. The construction illustrated is that obstructed pathfor .the liquid to diffuse outwardly. It is generally preferable tolsurround the outflow area with suitable balliing means as exemplied bythe cylindrical baille 40 which may be supported from the carryingmembers 35 by means of framework indicated generally at 3l, in Fig. 1.In that construction, of course, the baille 40 rotates with the tubularmember 36 and the carrying members 35. However, the baille mightconveniently he supported in a stationary manner, by suitable' means,from the platform 22 or the platform 30, or in anyrother desired manner.In the latter case it would, of course, not rotate but would remainfixed. The purpose of the bame 40 is to cause the outwardly diffusingliquid to assume a generally downwardpath into the body of the tankadjacent the central portion in order to permit the more readilysettleable material to deposit on the tank bottom near the centralportion thereof and thus eliminate unnecessary raking of that materialto a considerable extent. .y

vIn order to prevent liquid entering the lower part of the tubularmember 35 from the receiving section I5, from escaping belowthe lowerend of degree. A'simple, butat the'same time, highly effective sealingmeans is shown in the drawings wherein the tubular member 35 is seen toter-I minate a short distance above the tank bottom and abovethe upperend of the receiving section I5. Adjacentits end the tubular member isprovided with a series of openings about its periphery through whichextend bolts 42. The shanks of the bolts 42 extend through vertically 3slotted openings in an apron 43 telescoping about the end .of thetubular member. Thus the apron 43 is adapted for llimited adjustment ina vertical somewhat spaced laterally therefrom' to provide a step orseat 45. It will be seen that the curbing 44 is spaced suiliciently fromthe edge of the well I4 and with relation to the diameter of the tubularmember 35 and apron 43 to insure a small annular space 45 between theouter surface of the apron 43 and the inner vertical face of thecurbing. 'When the machine is erected and before being put intooperation, the apron or skirt 43 is adjusted vertically so as toapproin'mately --rest on the step or seat 45 but so as not .to bind orinterfere with free rotation of the mechanism.

This in itself, coupled with the` tendency of the,

liquid to continue its upward ilow, tends to prevent the escape ofliquid past thelower edge of the skirt 43 in any substantial quantities.How-- ever, as the sedimentation operation is continued, depositedsediment or sludge will build up on the bottom of the tank and willeventually work its `way over the curbing 44 and substantially fill thebalancing eiect of the hydraulic pressure within the receiving sectionI5 and the upilow terminal portion 35, and within the body of the tank.The hydraulic head of the body of liquid within the tank will somewhatbalance, or at least oppose to a considerable extent the pressure of theliquid rising within the feed conduit. Thus this small pressuredilerential plus the sludge seal will very effectively prevent anyserious, escapage of liquid past the lower edge of the skirt 43.

The construction provided at the lower end ofthe turnable tubularmember. or drum- 36 on the one. hand and at the upper end of themarginal wall of the wellor stationary influent pocket section I4 on theother hand, constitutes or provides that which may be referred to as aringshaped type of sealing construction. This sealing means embodies injuxtaposed relationship and in cooperative arrangement relatively xeclringshaped sealing section or member provided by or at the upperv end ofsaid marginal wall -and a horizontally-tunable ringshaped 'sealingelement provided at or by the lower end of theturn.

able tubular member or ldrum, 35, to wit, by the vertically adjustableapron -.or ring 43. The important feature of the construction by whichthe l lower end of the turnable drum and the marginal wall are broughtinto cooperative relation is that they shall have such proximatearrangement relative to each other whereby as the apparatus functionsthere is prevented any substantial escape of influent liquid fromvbetween the stationary marginal wall on the one hand and the lower Aendof the turnable drum or tubular carrier on` the other hand. The lowerend of the tubular carrier is in substantial register with the upper endopenings of the well I4 and thus the inflowing liquid passing from thewell flows therefrom directly into the vlower end of the tubular carrierthence upwardly within the space thereof about the pier to the liquiddischarge areas or openings provided in or by the carrier.

hollow columns are necessarily limited in crosssectional diameter due toconstructional diiiiculties and costs. The upiiow feed terminal memberof the present invention can be constructed with large diameters at aminimum expense and difficulty to give sufficient cross-sectional areasto provide for large volumes of flow and to insure a laminar andnon-turbulent upflow and subsequent diffusionv into the contents of thetank. Furthermore, by-being able to directly join the inner ends of therake arms 31 by means of the struts 39, the torque action is carriedstraight through the center assembly and its eiiects upon that assemblyand the actuating mechanism therefore are reduced to a minimum.

Thus, the sedimentation tank feeding arrangement of the presentinvention provides a relatively light, eilicient and easily fabricatedstructure, which eliminates fo er costly construction expenses, whichwill pro Ade for introducing feed in large flow volumes, which willinsure a steady and non-turbulent influx of liquid into the tank. andwhich possesses other features and advantages which the art.

What is claimed is:

1. sedimentation apparatus comprising a tank having a bottom and sides,an eiiiuent overflow that determines the operating liquid level therein,sediment discharge means, a fixed pier. a turnable member comprising atubular drum having at the lower portion thereof a ring-shaped sealingelement and also having liquid release'area, arms extending from thedrum and rotating therewith, blades on lthe arms for acting upon thesediment on the tank bottom. means associated with the pier from whichsaid tubular drum is rotatably supporteda motor and speed-varyingdevices for motivating said drum, and a fixed conduit for incoming feedhaving an upiiow discharge section disposed at the base of the pier anddischarging into the lower end of the tubular drum and. having at theupper portion thereof a stationary ring-shaped sealing element that isjuxtaposed and cooperatively related to the ringshaped sealing elementof lthe tubular drum whereby the drum forms a rotatable terminal sectionof the otherwise xed conduit and the pier is surrounded by saidrotatable terminal section as well as by liquid iiowing upwardly throughsaid rotatable terminal section.

2. sedimentation apparatus comprising a tank having a bottom and sides,an effluent overilow that determines the operating liquid level therein,

sediment discharge means, a fixed pier-providing structure, a tumabledrum having a release area and a ring-shaped sealing element, armsextending from the drum and turnable therewith, blades on the arms foracting upon sediment on the tank bottom, means associated with thepierproviding structure from which said drum is rotatably supported, amotor, speed-reducing means for actuating said drum from said motor, afixed pocket-providing section sunounding a lower portion of the pierand having a stationary ringshaped sealing element juxtaposed withrespect to and cooperatively associated with-the Sealing will beapparent to tho skilled in' 'a2-sensa element of the turnable drum forcompleting the liquid-sealing structure between the fixedpocketproviding section and the turnable drum. and a conduit incommunication with the pocket in the fixed pocket-providing section.

3. A sedimentation apparatus comprising a tank having 'a bottom andsides, discharge means leading therefrom, a stationary column-providingstructurev rising from the bottom of the tank, a

, vertical tubular carrier having liquid release area and having acircular horizontally-turning sealing portion, arms extending laterallyfrom the tubular carrier and disposed for horizontal rotation within thetank about the column of said structure, means associated with thestationary structure and from which said tubular carrier is rotatablysupported, means for turning said tubular carrier, and a xed influentsupply section having a fixed ring-shaped sealing portion flinctionallyassociated with the circular'horizontallyturning portion of the tubularcarrier'whereby liquid flowing from the nxed iniluent supply sectionpasses into the'tubular carrier and whereby there is substantiallyprevented leakage of the liquid from between the associated ilxed andhorizontally-turning sealing portions, in which apparatus the tubularycarrier functions not only for supporting and turning the arms, but alsoto provide a rotatable terminal ofthe influent -supply means, and withinwhich rotatable terminal the inilowing liquid continues to ow upi wardlyalong a passageway in the spaceleft between the interior of the tubularcanierand the exterior of the column to the liquid of the carrier. l

4. An apparatus of the class'described comprising a tank with a bottomconstruction providing a pocket section open at the top with astationary'sealing portion along the upper margin thereof, a stationarystructure comprehending a column extending upwardly from the pocketsection and leaving an initial liquid-receiving region within the pocketsection, a liquid feed conduit section delivering into said initialliquidreceiving region, a sediment discharge leading from a section ofthe -tank interior that is spaced from the liquid-receiving region,outwardly exrelease area vtending arms functionally disposed within thetank, and a horizontally turnable carrier for said arms mounted so as toderive support from said stationary structure, said carrier having aver- Atically extending horizontally-tumble. tubular body provided atthe upper portion thereof with a discharge area leading from theinterior thereof and having at the lower portion thereof a turnablesealing portion juxtaposed and cooperatively disposed with respect tothe stationary sealing portion so that innuent received into the initialliquid-'receiving region is compelled to pass therefrom into the lowerend of the horizontally-turnable tubular body and upwardly along theupilow space within the tubular body and therefrom through the dischargearea into the tank.

5. An-apparatus of the class described comprising a continuouslyoperable settling tank with a bottom construction providing a centrallydisposed pocket section open at the top with a stalow the bottom ofthetank and delivering into said initial liquid-receiving region. asediment discharge pipe leading from the sediment-receiving sump,eilluent withdrawal means determining. the normal operable liquid levelwithin the tank, outwardly extending .arms functionally disposed withinthe liquid holding section of the tank, a horizontally turnablevertically extending tubular carrier for said arms mounted so as toderive support from said stationary structure,

vand means for turning said tubular carrier and the arms extendingtherefrom; said carrier encircling said column and having sumcientinternal area to leave an upiiow space therein between it 4and thecolumn; said carrier also being provtu'rnable carrier for the vided atthe upper portion thereof with discharee area leading from the interiorthereof and at the lower portion thereof with a turnable vsealingportion cooperatively disposed-with respect to said stationary sealingportion so that influent re` ceived into the initial liquid-receivingregion passes into the tubular body and therein upwardly along theupilow space within the tubular carrier and then through the dischargearea into the liquid holding section of l 'arms also provides a turnableupfiow terminal of the conduit by which liquid to be treated isdelivered into the tank.

JOHN H. KNowrEs. 15

the tank wherebyy the 10

